# AP CHEM

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Please help me with these AP Chemistry homework problems and show me the steps how to find the solutions:

Liquid-Liquid Tirations: What is the concentration of the unkown solution for each of the following titrations?

#5) 25.36 mL of 0.178 M NaOH is required to titrate an 25.00 Ml of an unknown concentration HF acid solution?
NaOH(aq) + HF(aq)--> NaF (aq) + H2O(l)

#14) 45.32 mL of 0.0200 M KMnO4 is required for complete titration of an 7.00 ml sample of decomposed blood. What is the molarity of iron in the blood sample? (Note: The blood sample is treated to destroy the hemoglobin and then to reduce iron to iron (II) ion. These steps have no affect on your calculations.)
8H+(aq) + 5Fe2+(aq) +MnO4- --> 5Fe3+(aq) + Mn2+(aq) + 4H2)(l)

#19) 34.09 mL of 0.251 M KOH is required to titrate a 10.2951 g sample of acetic acid. The density of the solution had been prevously found to be 1.007 g/mL. What is the molarity of the acetic acid solution?
KOH(aq) + HC2H3O2(aq) --> KC2H3O2 (aq) + 2H2O(l)

• AP CHEM -

1. Write the equation and balance it.
2. Calculate mols titrant added. mols = L x M
3. Convert mols titrant to mols unknown. You do this conversion with the coefficients in the balanced equation. Just the same as dimensional analysis.
4. Convert mols unknown to Molarity from mols = M x L